Drilling rig with hinged, retractable outriggers

#The present invention is drawn to oilfield drilling structures which may be easily moved from one drilling position to another by use of outboard, hinged outriggers. These structures are useful in drilling oil wells in fields where a great many boreholes are required to sustain the production of oil. The invention further provides a drill rig having features which allow it to be transported along roadways from one oilfield drilling location to another.

#There are numerous patents and publication regarding ‘mobile’ oil well drilling rigs that may be transported in a ‘stowed’ mode along public highways and which may also be moved in an ‘erected’ mode when drilling multiple adjacent wells within a particular oil field. One such patent, U.S. Pat. No. 3,754,361, incorporated by reference herein for all it discloses, discussed a wheeled structure to transport a drilling rig with rotatable wheel assemblies which allow the rig to be moved by using a ‘fifth wheel’ arrangement which may be rotated to any angle. These wheels are permanently attached, however, which may consume considerable space and add unnecessary weight.

#U.S. Pat. No. 4,375,892 discloses a more flexible ‘dolly type’ structure which also allows a rig to be moved in any desired direction. However, this structure shares many of the same general problems as U.S. Pat. No. 3,754,361, as described above.

#FIG. 1 is a side elevation view of a drill rig of the present invention.

#FIG. 2 is a cut-away top view of wheeled frame dollies arranged to lie within the support columns of the drill rig of FIG. 1.

#FIG. 3 is a side elevation view of the drill rig of FIG. 1 arranged for transport along a public highway.

#Turning now to FIG. 1, the drill rig 12 of the present invention is a transportable type of drilling rig which allows it not only to be moved short distances such as the several hundred feet from one wellbore to be drilled to the next as illustrated in the configuration shown in FIG. 1, but which also may be disassembled, packaged and towed (as shown in FIG. 3) over public highways from one location to another which may be hundreds of miles apart.

#Since a fully assembled drill rig 12 may weigh several hundred tons, moving it for even very short distance may be challenging. The drill rig 12 of the present invention may be placed upon one or more wheeled frame dollies 18, which are fitted with a number of wheels 14 (as shown in FIG. 1) and may be pulled along by a single towing bar 16. In some cases the wheeled dollies 18 with rotatable wheels 14 are towed to the next well site by each of their individual tow bars 22, as shown in FIG. 2.

#Alternately, (and preferably) these dollies 18 may have motors built into their wheels 14 which allow them to be self propelled. In this case, each of the wheels 14 of the wheeled dollies 18 may be independently powered and individually and independently turned to the left or right to steer the drill rig 12 as it is being moved. In addition, the dollies 18 may have built-in jacking devices which allow them to be placed under the substructures 24 and elevated to contact and lift the drill rig 12. The drill rig 12 of the present invention as shown in FIGS. 1-10 is adapted to be carried upon these wheeled frame dollies 18.